Electronic brake system and method for operating same

Patent metadata

Field	Value
Publication number	US-11993232-B2
Application number	US-202017614354-A
Country	US
Kind code	B2
Filing date	Apr 29, 2020
Priority date	May 31, 2019
Publication date	May 28, 2024
Grant date	May 28, 2024

Abstract

Provided is an electronic brake system including: a reservoir in which a pressurized medium is stored; an integrated master cylinder including a simulation chamber, a simulation piston provided in the simulation chamber to be displaceable by a brake pedal, a master chamber, a master piston provided in the master chamber to be displaceable by a displacement of the simulation piton or a hydraulic pressure of the simulation chamber, an elastic member provided between the simulation piston and the master piston, a piston spring elastically supporting the master piston, a simulation flow path connecting the simulation chamber to the reservoir, and a simulator valve provided in the simulation flow path to control a flow of a pressurized medium; a hydraulic pressure providing unit provided to generate a hydraulic pressure by operating a hydraulic piston according to an electrical signal output in response to a displacement of the brake pedal; a hydraulic pressure control unit including a first hydraulic circuit provided to control the hydraulic pressure to be transferred to two wheel cylinders, and a second hydraulic circuit provided to control the hydraulic pressure to be transferred to other two wheel cylinders; an electronic control unit configured to control valves based on hydraulic pressure information and displacement information of the brake pedal; a backup flow path connecting the simulation chamber to the first hydraulic circuit; an auxiliary backup flow path connecting the master chamber to the backup flow path; and an inspection valve provided in the auxiliary backup flow path to control a flow of the pressurized medium.

First claim

The invention claimed is:

1. An electronic brake system comprising:
a reservoir in which a pressurized medium is stored;
an integrated master cylinder including a simulation chamber, a simulation piston provided in the simulation chamber to be displaceable by a brake pedal, a master chamber, a master piston provided in the master chamber to be displaceable by a displacement of the simulation piston or a hydraulic pressure of the simulation chamber, an elastic member provided between the simulation piston and the master piston, a piston spring elastically supporting the master piston, a simulation flow path connecting the simulation chamber to the reservoir, and a simulator valve provided in the simulation flow path to control a flow of a pressurized medium;
a hydraulic pressure providing unit provided to generate a hydraulic pressure by operating a hydraulic piston according to an electrical signal output in response to a displacement of the brake pedal;
a hydraulic pressure control unit including a first hydraulic circuit provided to control the hydraulic pressure to be transferred to two wheel cylinders, and a second hydraulic circuit provided to control the hydraulic pressure to be transferred to other two wheel cylinders;
an electronic control unit configured to control valves based on hydraulic pressure information and displacement information of the brake pedal;
a backup flow path connecting the simulation chamber to the first hydraulic circuit;
an auxiliary backup flow path connecting the master chamber to the backup flow path; and
an inspection valve provided in the auxiliary backup flow path to control a flow of the pressurized medium.

2. The electronic brake system according to claim 1 , wherein the hydraulic pressure providing device comprises:
a first pressure chamber provided on one side of the hydraulic piston movably accommodated in a cylinder block to be connected to one or more of the wheel cylinders; and a second pressure chamber provided on an other side of the hydraulic piston to be connected to one or more of the wheel cylinders, and
wherein the hydraulic pressure control unit comprises:
a first hydraulic flow path in communication with the first pressure chamber; a second hydraulic flow path branched from the first hydraulic flow path to be connected to the first hydraulic circuit; a third hydraulic flow path branched from the first hydraulic flow path to be connected to the second hydraulic circuit; a fourth hydraulic flow path in communication with the second pressure chamber; a fifth hydraulic flow path connecting the first hydraulic flow path to fourth hydraulic flow path; and a sixth hydraulic flow path branched from the first hydraulic flow path to be connected to the fifth hydraulic flow path.

3. The electronic brake system according to claim 2 , wherein the hydraulic pressure control unit includes a first vale provided in the first hydraulic flow path to control a flow of the pressurized medium and a second vale provided in the sixth hydraulic flow path to control a flow of the pressurized medium.

4. The electronic brake system according to claim 3 , wherein
the first valve is provided as a check valve for allowing only a flow of the pressurized medium discharged from the first pressure chamber, and
the second valve is provided as a solenoid valve for controlling bidirectional flows of the pressurized medium.

5. An operation method of the electronic brake system according to claim 4 , comprising
a first braking mode in which, as the hydraulic pressure of the pressurized medium transferred from the hydraulic pressure providing unit to the wheel cylinder gradually increases, the hydraulic pressure is primarily provided according to a forward movement of the hydraulic piston; and a second braking mode in which the hydraulic pressures is secondarily provided according to a backward movement of the hydraulic piston after the first braking mode.

6. The operation method of the electronic brake system according to claim 5 , wherein in the first braking mode,
the second valve is opened, and
the hydraulic pressure generated in the first pressure chamber according to a forward movement of the hydraulic piston is provided to the first hydraulic circuit by sequentially passing through the first hydraulic flow path and the second hydraulic flow path, and provided to the second hydraulic circuit by sequentially passing through the first hydraulic flow path and the third hydraulic flow path, and
at least a part of the hydraulic pressure generated in the first pressure chamber is provided to the second pressure chamber by sequentially passing through the first hydraulic flow path, the sixth hydraulic flow path, the fifth hydraulic flow path, and the fourth hydraulic flow path.

7. The operation method of the electronic brake system according to claim 6 , wherein in the second braking mode,
the second valve is closed, and
the hydraulic pressure generated in the second pressure chamber according to a backward movement of the hydraulic piston after the first braking mode is provided to the first hydraulic circuit by sequentially passing through the fourth hydraulic flow path, the fifth hydraulic flow path, and the second hydraulic flow path, and provided to the second hydraulic circuit by sequentially passing through the fourth hydraulic flow path, the fifth hydraulic flow path, and the third hydraulic flow path.

8. The operation method of the electronic brake system according to claim 7 , wherein in a releasing of the second braking mode,
the second valve is closed, and
a negative pressure is generated in the second pressure chamber according to a forward movement of the hydraulic piston such that the pressurized medium provided to the first hydraulic circuit is recovered to the second pressure chamber by sequentially passing through the second hydraulic flow path, the fifth hydraulic flow path, and the fourth hydraulic flow path, and the pressurized medium provided to the second hydraulic circuit is recovered to the second pressure chamber by sequentially passing through the third hydraulic flow path, the fifth hydraulic flow path, and the fourth hydraulic flow path.

9. The operation method of the electronic brake system according to claim 6 , wherein in a releasing of the first braking mode,
the second valve is opened, and
a negative pressure is generated in the first pressure chamber according to a backward movement of the hydraulic piston such that the pressurized medium provided to the first hydraulic circuit is recovered to the first pressure chamber by sequentially passing through the second hydraulic flow path, the fifth hydraulic flow path, the sixth hydraulic flow path, and the first hydraulic flow path, and the pressurized medium provided to the second hydraulic circuit is recovered to the first pressure chamber by sequentially passing through the third hydraulic flow path, the fifth hydraulic flow path, the sixth hydraulic flow path, and the first hydraulic flow path, and
the pressurized medium in the second pressure chamber is supplied to the first pressure chamber by sequentially passing through the fourth hydraulic flow path, the fifth hydraulic flow path, the sixth hydraulic flow path, and the first hydraulic flow path.

10. The electronic brake system according to claim 4 , wherein the hydraulic pressure control unit further includes a third valve provided in the fourth hydraulic flow path to control a flow of the pressurized medium.

11. The electronic brake system according to claim 10 , wherein the third valve is provided as a solenoid valve for controlling bidirectional flows of the pressurized medium.

12. The electronic brak

Assignees

• Hl Mando Corp

Inventors

• Kim Jin Seok
• Choi Seong Ho

Classifications

• B60T13/686 Primary

  in hydraulic systems or parts thereof · CPC title

• B60T7/042 Primary

  by electrical means, e.g. using travel or force sensors · CPC title

• B60T8/4086 Primary

  the stroke simulating device being connected to, or integrated in the driver input device · CPC title

• B60T13/142

  Systems with master cylinder · CPC title

• B60T13/62

  both straight and automatic · CPC title